Generally, a hinge assembly for a display appliance used in a personal computer includes, as shown in FIG. 1, an L-shaped mounting plate 3 having a vertical portion 3b formed with a hinge shaft receiving hole and a horizontal portion 3c at one side secured to a casing body of the display appliance; and a hinge shaft 1 having a mounting portion 1a secured to an upper cover of a casing of the display appliance, an extended portion 1c at the other side pivotally inserted into the hinge shaft receiving hole of the mounting plate 3, and a flange 1b between the mounting portion and the extended portion. The extended portion 1c has at a free end thereof a faceted portion 1c′ with a threaded portion formed thereon.
The hinge assembly also includes washers 2a and 2b disposed at both ends of the mounting plate, an axially biased resilience washer 4, a sleeve member 5 contacted with the resilience washer 4, a torsion spring 6, a washer 7 restricting a pivoting range and having a stopper boss 7a, and a nut 8.
The sleeve member 5 has a flange portion 5a contacted with the resilience washers 4 and a tubular portion 5b receiving the torsion spring 6 therein. The torsion spring has one bent end 6a inserted into a hole 3a formed at the vertical portion 3b of the mounting plate, and the other end supported by the stopper boss 7a of the washer 7.
The pivot range restricting washer 7 is formed with a hole having a shape corresponding to that of the faceted portion 1c′ of the extended portion 1c. Since the faceted portion 1c′ is inserted into the hole, when the hinge shaft is pivoted in one direction, the pivot range is restricted until the braking boss 7a reaches to the end 6a of the torsion spring 6. When the hinge shaft is pivoted in the counter direction, the washer 7 is applied with elasticity against the pivoting operating, since the braking boss 7a is stopped by the other end of the torsion spring.
Since the hinge assembly as described above requires the specially faceted hinge shaft, the hinge shaft has to be machined through a faceting process including milling and turning during the manufacturing of the hinge assembly, thereby increasing the manufacturing cost. In addition, separate components corresponding to the shape of the faceted hinge shaft must be manufactured, thereby complicating the design of the hinge assembly and making difficult to assemble the hinge. Furthermore, there is another problem in that the relatively soft plate of the components of the hinge assembly can be easily worn by the rotation of the hinge shaft.